And still, she said Tuesday, the Ryan Ferguson case was unlike any she'd ever taken on.

Zellner, a Texas native, orchestrated Ferguson's appeal of his 2005 convictions for the murder and robbery of Columbia Daily Tribune sports editor Kent Heitholt. She has gained a reputation for her work in wrongful conviction law.

She said she has never lost a wrongful conviction case.

"She's had a lot of success," said Steven Drizin, a clinical law professor at Northwestern University. "She's a big fighter for the wrongfully convicted."

Flint Taylor, one of the founding partners at Chicago's People's Law Office and a lawyer who is familiar with Zellner, echoed Drizin's praise.

"She has a great record," Taylor said. "She's known for fighting hard."

Zellner spent two years as a student at MU before moving to Montreal with her husband. There, she finished her undergraduate degree. She went on to get her law degree at Northern Illinois University.

Her office in Downers Grove, a Chicago suburb, has handled 15 exonerations, with 23 more in various stages. Three wrapped up during her time on Ferguson's case. In September, one of those clients was released after 23 years in prison.

Ferguson's is just the latest of Zellner's many high-profile and high-publicity cases. In 2005, her client Kevin Fox was released after eight months in prison. Fox was charged in the rape and murder of his 3-year-old daughter and was ultimately exonerated through DNA evidence. He later sued Will County, Ill. The jury awarded him and his wife $15.5 million.

Zellner's work with Joseph Burrows in the late 1980s and early 1990s is even more eye-opening. Zellner spent months in discussion with Gayle Potter, one of the original suspects whose testimony helped convict Burrows. Potter eventually recanted her statements and pleaded guilty to the murder.

She's "a force to be reckoned with," Drizin said at least three times in a five-minute phone conversation.

Perhaps the most bizarre case Zellner worked on was nearly made into a movie. Larry Eyler, a death row inmate and Zellner's client in the early 1990s, confessed to her that he had killed 21 men and boys. Eyler died of AIDS while on death row for another murder. Two days after his death, Zellner called a press conference and detailed her former client's gruesome crimes.